Hi Dru,
I am with the AC Quality Assurance Department
Read your question and it seemed very familiar
I logged this as a bug back in 2016 and it was closed as the spell checker was never implemented to work on the Addendum form
My suggestion to you is to submit a Recommended Improvement through Amazing Charts (Help > Recommended Improvements)and the Product team will see it and log it
If there are enough requests it can eventually be implemented (not sure how many requests it takes to move forward)
Thanks and have a great day
Anthony@AC
